SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e47d376742d2cde986586efdf78f80fa40f9b8725b186dfc81dee8a50fefb095' 
  AND token = 'Q2/8n8I2vYAfLOjYwFYeiYCOEMpYu0xI95LnVEmF4yY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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