SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6fc6cdc72f77d22c599b605752c07671f0344a5e93aaff7c9875a1efd9ccebb0' 
  AND token = 'mSjakNgocxUPPapB3vZB4Sww0VTdEdiLik+HLBq/qzg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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