SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9f3419b2523138416f9a2ff4ad6c4ff15756268e528f362f6319b48a4a355f6c' 
  AND token = '2yNvWw9VJ7ZRqjg+82YdQpFnXTLUguJsstOT6hJpZHc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00054

JSON explain

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