SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '55d43b3b7c523fad15475882879985aa4b2573f86bc2d908bde2000b4313cbf2' 
  AND token = 'oHtJYAEEtmF1jkENdPQOHansHnOOSMZdeSDAX8hH9oE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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