SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '26c7efca960ea163b2ec1fb552ed819967ad80b84950862c4774b15652ce70f9' 
  AND token = 'mAzGdqbl8Yd9zsVaryhKmunOx80F7zrUf2t67ydzD7M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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