SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'df669989832b2340240fbe13578417b1d36d67db22cf79e2524719d62c99c88e' 
  AND token = 'oYszrdk1I3xKMWs+WhLa9ZizRcOCNhzXGgiFXY1qRMU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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