SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c6961861ad39e162981a8b7b064a6709b23e867432d588648b50abe4194adadb' 
  AND token = 'IKxtcMhqhwaYCKcJbMt2sPSWjWvQk9J1/FZ5sjCHCpY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}