SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b45f8ff7fcefa3a22a402af4b1ee614aebcbc787bf70e1563ae545f47fa9d3ab' 
  AND token = 'VRQDaIl65EmOse3a06LWdDfP9dsEtTm/7I4P0IASZ1U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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