SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3a489d84bd9d94bf421acef5742f4469c568a49dcf4d62c481472cd754a1da2d' 
  AND token = 'lyzfmfCjDXr7cNbT7YsMJYtjqQ/TLfXJWbpLEsRKvew=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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