SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1e1764eb388536eb2be06f9dff648486cf1d6469dc39b3858c68e4e87102a0d1' 
  AND token = '0ZO/k7S8VTS1cYdGwsonQqOtjvdz3G2xCqLmuCHRRVg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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