SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '39e432f72e0516189405bfacc47e1c0e287b651bec57e46c95749a8a6905f3a3' 
  AND token = '74hKKHmBx03DyHrQ/vbh7ICRLAYuHR7y1BK19Gxz/BA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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