SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'ba0367eddb6ac67e922bdd9ec7cb95d5c80c73385740df9974c321bc02b71b7e' 
  AND token = 'A6/QciiNhnhVu7zmmDZrreltQ+qHhxw4uRIkCvH+GHQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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