SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c62602ba9101e746487041cebaadc9878c80fad332b7e857d25d88aefcdd94a4' 
  AND token = '0wvNrgt0sK1jvgyDySw3ohmG7OVkr2yvpzgmrvZD3ZU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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