SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '231671166cd4bd3514c5daabfbce20edd0a352eb7fbbb248ab4d51b8c9bb599e' 
  AND token = 'XRQNPMCommrQWzlVUmAoJC+qhR0480TRSyKkOLwudm4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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