SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f8f4b2fba520bfada5c61fc476d760f8ac0d1fcadc14db2881baa932b2517e9a' 
  AND token = 'A0gGXZmtQDTaYHFHH41eaCEqcN+b2Y8MWgfdzZQwYUI=' 
  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"
    }
  }
}