SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5bef2461f69e41b2d9928d6c134f5359138b4219b949c3f87ad6220d2c50016a' 
  AND token = 'MowVrcfOL6NAuZK9p8zg/YqigkI/PFlBwP8mG3x5JLY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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