SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '399552b52e6a30c6d19ec756b150f9e11ae29e89642f5b534cbe43e3ddfba67f' 
  AND token = 'eagWPGJS2cxAnY5Z05sQBQVlsHmXFMVWuSRhG+Wzhkk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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