SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4db35e75d40b5704f154aff197a5f72d8c85180059c6212f4d425d5ad04da48e' 
  AND token = 'zxaWAB6DNJDu+QdeOSIBfk5adfXXIgLfbaGH7cBGbMs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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