SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c090b23e28e66f582a85f8704305d1fb8f325e47e42968e7749528b846bb7afa' 
  AND token = 'ciYsEsFvSpeM3kRK67MQoUKS7ufvTCfG1at2Jmpq8IU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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