SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '122fd1bc2fade52eaedb2907729a5389191dcf42c49e811eab3981f03b93d1cd' 
  AND token = 'xk2kIwGdcw32YFE9ZQFVn1ywCo87ul/6B1M1VMK8nA8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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