SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '05fc6363b6996af38316de357d9989f74dcb2c208d3c6805a089514a98e49912' 
  AND token = 'BYJXcWrw648XJTljvRi6UFVKEcsWNxkbKyQWvBuLGCQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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