SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b30d4dfc33a9a49086a7826827889087332dc9f6bf6f7c16381b517f61db9608' 
  AND token = 'F7PPuygK85GDF4U9if+TWQZ+LUEJDVWpEGEmwxTCdAc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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