SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dbaf12e77a9cd565b4dd1ec47a31143d205645d0446d919ceebcbefa0462d197' 
  AND token = 'n+8lAKXdVotI7Vpv2E+OtJcsyAhB5JtQIevGy8IJMAo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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