SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'edf5dfc661b6efd1f88c23082cbb011e7177972484f96592d51a94e4d9ca1827' 
  AND token = 'sFXTJgLzaDNl+Q4IEiyVYkrcVggcEJoTp6OUFwugAdE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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