SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5cf02655d1d3a465d7d1c3d00d63cd50d678116288515d1899ab2e0eccc0d7e5' 
  AND token = 'XImYN9uuIahwxLUG5brXwNVHN9sjOBLInGtwzTw2Qfg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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