SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7d0be8746bb552bd199df322ea2f1b14a499fccb071c58f2cca31c8885d4720c' 
  AND token = 'bfN2fMppaLXi0YuKInkX84XUaGMgohosWIPRlYFB1Ic=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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