SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c7bf39521ab8bda13fa4b27d95ea8aae8cf63a1a9de725aaf32f2196696f53ea' 
  AND token = 'uuFHFAAl9asD1h+dC+jiTIRyHMtzOxNRQ7SUonDMEwg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}