SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e7a2cc65f203373188c522decbb25965d1b1742fbb67b3bca46178d1833de607' 
  AND token = 'qL5TYT5lMArO21rWoENarrZaRTnWO7lPjvxt88GGlwg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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