SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dcf7f0f205ddea593e2f1af6c65ec2f66b4eefcc15efa849606f9f8571b55ed4' 
  AND token = 'qwoNoPeVO6pNDKBemDXrEUSvhtSvoa0XznlAShERsxY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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