SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f71e4549c2dc909c63dba2abebb32dbab1548ce15cad43dff90b7364afe60cd1' 
  AND token = 'fgedBubxKa+DDJ5fFTGhN+r/LdsCavi78FCYYXbeD2s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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