SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b24561a0b30e66365fef672123d960834fcf43480f1166cc62a7576902cf9e9b' 
  AND token = 'btA43qCO83tFyYW2Y7+ViFCpAHjFdwzr8qTiyxNJqrw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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