SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8733078e602f70912ccdcca87df43a819b18bb27de94dfa35c389b6a2b64656a' 
  AND token = 'uvocV190JdxfDy82jM/z/XfY/C3ifiRyl97oDlYdunE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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