SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd28b299d90368fc5111d90bb3424da6b22d192a572769da0b44dd65ab621b697' 
  AND token = 'B0UNsYy1367gIUGafbeKIgYw4Fu+6nX7D65I3QOKgUk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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