SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5b8e01ca11783edddfc7b85820d4be26fa88526fbb41b5ed71bb433149540f37' 
  AND token = 'kKPLRpYStieFXCzOzw075seBdV3C5iPtGSFAq1KEuO4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}