SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '853e9fe823348ca149d3d114e7498fc0169af6bdbd78c65bfbf2b7d7d645a360' 
  AND token = 'gdi2ApRI7c05JMcL/m2uKaUZHHT+EAnXvzQKYti/9ro=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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