SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '81f369ea57ea8cf60793844347d1d4add82c2c037d0879ee3b1ab7e0d576f847' 
  AND token = 'xEcgf+aq+TTetE2H9+9KuUuqRvy0+d8q9CsKw0Xs1h4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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