SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '524e205f1f62d94dec0196018de78cc91b752821c4af19144eb0f718530ea79b' 
  AND token = '5tKdskZVz76/KfFdWZcIT1zNrchvcyL9axBQVkas7L4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}