SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '2db23b40150cbfd86c2115bb3679657c6f66d541c27d904d24cad4c9dcd17dd6' 
  AND token = '9bwTFu5KwLP6bHSxsFTYXMKL9hReyumEli/3DizdRVA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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