SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '58bc2949dcb968e42b02fd47a69a213716338058bef34d2993eeae31aa6027f5' 
  AND token = 'tshBVXvvjtqTdzY1UYW1PzBTiq6pyljAec2ANci5niM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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