SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'e422d746883c1c114b5d5a216fcd2f89353f94f66b28de5d9236a66584a6f3bd' 
  AND token = 'GFOugylnvKNiq4xvblJMf6L+bAhkM7eDu7B+yhxgjF8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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