SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ee069c8a5344186a4700ecf0b6f3979a990a6821dca9fa8696234b5321e43150' 
  AND token = 'BWA0rk+NxRWyuiH7VhLH6Nh9uEcj3IxaVXhCTXKTjLo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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