SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b0bf16f5dd24e5b126ebdf7b3a7860e316fcec0b3a9003c25a4f75a99a7b6ba6' 
  AND token = 'EE4GKY25b6LMZAJH7lMfLbY9YpCLGuN/dOOB3lr82SA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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