SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e7f5909542d626f1a4b9402a19686031ca8e0d3283575de2ac6b4b3449f322f2' 
  AND token = 'zTq6YM8TaDWf0PT6tuZWKg7PfFflZKjUYf9JJ7mOjpI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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