SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3d10cb8597e515f9d530888c88d7cdbe686144b8e4a73821f3da724639ae0f5b' 
  AND token = 'M4zT1I7UuP917wKXobZTGPg8cVfenkSEQkikB6+kpBo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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