Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fc76fbc2f88aa608196b414e42bf9c3632f141c0edb59f75a8a5cd02f488e585' 
  AND token = 'qfa9XhmtsQLkLvT5Q/sR97gTMA4rQMLjHStUM5WC+WA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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