SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eaf4f8fb5c425d17258ca9a19964c151db7a230ea21aa57d29cfd79ad2a648f7' 
  AND token = 'Qu8c37PvImvSq9bHGQs8d9PmxU6e7XhGAKnOMTZL800=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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