SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'baf512f9a04787b762b86f6f308aac959a58997fe1057b77d44911d6bcb6950d' 
  AND token = 'TsOLdJAKN1AaJTOh/m8JGeJNu3Y9vZ8pwuMvDP9cqns=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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