SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f7e88afa95f0a6276c4b04a98dac7044ac033bfc2388c855bcf3866c622b644e' 
  AND token = 'TJvtvV+UsNCLTYp4mBUkuayYRQzypt7d40vibK5dS3c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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