SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '77f4be7f6e7bf57ef3df9db7943ad3c02c1e6609153bcfa7e1200b30ada78168' 
  AND token = 'c8XMn3TBMGCVFWZnyd/G/0J2/VZgwNBev8h1BRSLZxQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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