SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '891ad9888831401e14d7b66eef6ea0a4a310e40a1c702dd95cf416a2786cd201' 
  AND token = 'QixlUR1wHKPTX//L1ll7o+wl9P0/KKrVqhaC0Sqib44=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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