SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd9c6e78f7fa9351c68ce5b098fd6a8ae5a4dd8f144e411fd458db942b864eab5' 
  AND token = '3qX0br0OWDBJd0FAEylqtihFxJjwg+FMNNgJjdBx0mY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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