SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dbb011533b1e1151ef49b3a33238886f7c0964b8c6d25339e7354509928b4a0d' 
  AND token = 'g9TOVeIbj7/ILM5E8jDv4H+HYqcXhplHIJkFYn5Cpts=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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