SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b222641c99c7f6bffb26bcbf13869f248a9c24f5e6804e01e52d0cd08b542f1d' 
  AND token = 'vFRpXPm3vBG4uJWmSxAbqYL4zYvfJnvQjdGkEZbEUOY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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