SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '25caf9c4c4952e2686cd183aa860f1c37518cfb85f8e2117e4f56e4e5e719ce3' 
  AND token = '+QLUOUSdplWnmmeYOOURkoRrqcwoOzQrQYBk0sRS4sE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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