SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '488b8b27425124ab6b8573256f9130056deb9506c2a690d3fb5cff5e4a765856' 
  AND token = 'H4sViSmYb1cgkd+1hC2frvaVoMujRTA0Lty28rgor64=' 
  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"
    }
  }
}