SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '77a25c35d10b4eea13dfe3575145e618438c32b9480d60fd477af534d44d01f7' 
  AND token = 'SZalTyr32ozdnrQ8t3Jeh1rxE5JOIyHuBPGOXxeb57g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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