SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6126da4d19652c489f797470c9ad548c878b7a9a50e651bdaab48ad6cc69be26' 
  AND token = 'EO77yeA+lT/BJOjsvf+k/VaOwpBNnVIRLogrcvKZ37o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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