SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '39f4253c3eceaa40c8db31dab33164eb78fca77e2c30487aa69a958691664119' 
  AND token = '5zhLNASMMfShBJiXXSKLr5JUgGIhyqTLcpp45YOBgsY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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