SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '69f510cf7d584a5fef74c22f227012078aaa434fff64286f40d36a441b142ee8' 
  AND token = 'ztQ4b9PBYnlowyYok3wyaF90j2ijlqZJViv/pQRWEXk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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