SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b8d871f0938a3f14b8f22ae5795cbeced9871c592bb858837c9e96678953c369' 
  AND token = 'XB+/qFueJrvKMNOvZfGFws0/YhVdlVKn5dpGdNZCkW0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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